Device for preventing the transmission of sound.



W. C. SABINE.

DEVICE FOR IDREVENTING THE TRANSMISSIOII 0F SOUND.

APPLICATION FILED JULY H, ISM.

1,2?25838.k Patented Feb. 22, 1916.

IVM/ars Tr: a;

WALLACE C. SABINE, 0l* BOSTON, IASACHUBETTS."

Spection of Letten-Patent.

Patented Feb; 22, 1916.

Application July B, 1914. lBerill Kofwl.

To all whom t may concern.'

Be it lknown that I, WALLACE C. SABINE, of Boston, in the county ofSuffolk and State of Massachusetts, a citizen of the United States,haveinvented a new and useful Improvement in Devices for Preventing theTransmission of Sound, of which the following is a'full, clear, andexactdescription, reference being had to the accompanyin'g drawings,forming a part of this speciication in explaining its nature.

This invention relates to a\ device for preventing the transmission ofsound through supports or bearings subjected to pressure.

While I have in practice provided'sound insulation by the employment ofla discontinuity of material possessing diierencesinv elasticity anddensity, as forl example iron and felt, yet'under conditions of pressurethis fails, the pressure tending to eliminate the acoustical differencesbetween the strata.

It isA accordingly the essential object of my invention to provide forthe sound insulation of objects exerting 4pressure by a support orbearing practically impervious to sound vibrationl and which willpresent thegreatest acoustical discontinuity in its elements under thoseconditions of pressure to which it may be subjected.

The 'device embodying my invention essentially comprises a support orbearing in which the pressure is borne almost wholly by air or gaseousfluid compressed within an hermetic cell which tends to take up thevibration and the walls of which with relation to the compressed gas`furnish thediscontinuity producing the desired insulation.

The device comprising my invention can best be seen and understood byreference to' the drawings in which is vshown'embodiments thereof andalso an example ofthe application of the device.

In the drawings:-Figure 1 is a plan of one of the sound-insulatinghermetic cells. Fig. 2 is a cross sectional detail of anportion of thecell in conjunction with a supported object andA supporting base, theseparts be-v ing shown diagrammaticall Figs. 3 vand 4 are cross sectionaldetails of modified forms of the sound-insulating cell. is a crosssection showin a further embodiment of the sound-insu ating-device, andFig. 6 is a view partly in side 'elevation and partly in sectionl of aportion of a piano body, leg and the device applied thereto forsound-insulating the body. I

`the airv within the cell.

Fig. 5

' Referring to the drawings :-1 represents' the hermetic cell containingair or other gaseous fluid The wall 2 of the cell is made of thin metalor other material possessing radlcally -di'erent acoustic propertiesfrom The wall is also so shaped and so cmpressible that in practice theload is-substantially supported by the compression of air or gaseousfluid within the celL In order -to` prevent the transmission ofsoundthrough the metal around the edge lof the cell and to make the cellmore compressible it is '..provided with a flexible edge or rim 3. Sucheffect may be obtained in varlous ways as by bending or otherwisecorrugating the metal around the edge or rim-of the cell as shown inFigs. 2, 3 and 4. The cell is preferably made in separate half sectionsby dieing or stamping and the respective sections thensecured togetherand hermetically sealed in any suitable manner `as by soldering. A

The cell'permits of the use within it of some sound-absorbing material4`which augments the sound insulation-obtained bythe cell itself in thatwithin it.

In its application the device is placed be# tween the load or object forwhich thesupport provides a bearing, and the base to which thesoundvmight otherwise be transmitted from the object if the device wasnot used.` Such application is shown in Figs.

2, 3, and 4, in1which 5 represents the objectr y and 6 the base. In somecases a battery of cells is preferably employed. In such case A Ipreferablyassociate with the cells one or more plates or sheets 7 ofmetal. These plates form lnot only animvortant factor in diminishing thetransmission o f sound by roviding further discontinuity of media,

ut they also serve to distribute the pressurel uniformly over the cells.To make the application of pressure still more uniform and to preventalso the touching of metal surfaces which might lead to metallicrattling, I prefer to interpose felt or other non-metallic material 8between the plates 7 and the cell or cells'l. Owing to the fact that thefelt 8` is under heavy compression it 'has but little effect in theinsulation of sound.

The device is especially valuable in the support of pianos, the modernpiano leg being admirably adapted toreive it. .An

`it prevents resonance ing pressure' and a example of such applicationis shown in. Fig. 6 where l0 represents the body ofV the piano, 1l theleg provided with the usual metal port and to which the caster 13 issecured; The core l2 is lprovided with. a supporting head plate lt andbetween this plate and the body of the piano is located the insulatingdevice comprising my invention, the same being socketed within therecess' l5 preformed within the leg. 1With the parts thus arranged,v thepiano'rests upon the device which in turn'is supported by the core ofthe leg, the device vpmeventing the transmission ot'sound from the bodyof the piano to the core of the leg and iioor or base upon which thecore may be resting.

Having thus fully described my .invention, l claim and desire to secureby Letters Patent of the United Statesz-n Y l. The combination with anobject exertbase, or' a sound-insulat ing device interposed between saidobject and base holding the same out of contact with one another, saiddevice comprising an hermetic cell having a metallic shell the vmetal ofwhich is flexible and under tension and which cell contains a gaseousfluid.

2. A. sound-insulating device comprising an hermetic cell having acompressible, metallic shell containing a gaseous associated ,therewithmass.

3. A sound-insulating device comprising an hermetic cell having 'acompressible,

liuidvand a stratum of heavy core 12 which forms the main sup- .i "Malmanac metallic shell containing a gaseous tluid and associatedtherewithy a stratum of heavy mass and also a stratum of some soundfabsorbing material.

d.' .l sound-'risulating device comprising 4a compressible, hermeticcell containing both a gaseous fluid and some fibrous, soundabsorbingmaterial.

5. A sound-'nsulating device comprising a compressible, hermetic cellcontaining both a gaseous fluid and some fibrous, soundabsorbing-material, and associated. therewith a stratum of heavy mass.

6'. ln a sound-insulating` device, the combination of a plurality ofhermetic cells, each having a compressible, metallic shell containing agaseous fluid, and sound-absorbing material interposed between saidcells. 1 i

7. ln a sound-insulating device, the coin- Y bination of hermetic cellseach containing a. gaseous fluid, a metallic plate, and layers of somenon-metallic material interposed between said plate and said cells.

8. ln a sound-insulating device, the combination of hermetic cells eachcontaining a gaseous Huid and somesound-absorbing material, a metallicplate, and layers of some non-metallic material interposed between saidplate and said cells.

WALLACE C. SABNE.

Witnesses:

JOHN E. P. HAYES, M. E. FLAHERTY. A

